Thermostatic fluid coupling mechanism



April 7, 1953 c. JoHNsoN THERMOSTATIC FLUID COUPLING MECHANISM FiledFeb. '25, 1949 IN V EN TOR.

Illl III/III lll/111414 ATTRN E Y Patented Apr. 7, 1953 UNITED STATESPATENT OFFICE aeaacsr THERMOSTAT-Io FLUID eouPLlNaV MEQHANISM 1. Chilli.

rilieinvenuon, relates to. clutch mechanisme. and morerartcularlytQ-luth mecha-1.1.?. ms.

which operateY automatically in response `to changesin a condition for.controlling the 'con-f neotionof a driving member to a` driven member.In most automobilesl there. ,iS .Dlrdd afan which is .drivencontinuously for cooling y the motor` regardless of Whether or. notvsuch cooling action is needed.A By providing a clutch mecha; nism whichoperates to connect the fan in driven relation with the vmotor onlylwhen thev motor temperature exceeds a predetermined value, substantialsavings willr be made in the, energy ernployed fondrving-.the f-an., In.addition; t0.; the., saving of ener-gy. there` is maintained, especiallyduring the colder. weathelftemperature zondig tions at which-thevmotor.operates: more el: ciently. ItV will be appreciatedk thatarclutchmechanism of asimilartype may be made responsive to temperature whichvaries as a result of other changing'oriditions. For. instance, thedegree. toy which an automobile battery-is. charged may determine thetemperatueiectingopf eration of aclutchk mechanism toffcontrol thedriving of the generator bythe motor. `In other cases, .the clutch maybe madeoperative to conf trlthe driving. oa. compressor .in response tochanges'. in,its..discharge pressure.

.A preferred .form .of myinvention may nclude a vdriving..member havingan expansible device, such asabellowaxed for rotation therewith. Anuidwhich .expands or contracts. with changes in temperaturevmay'becenclosed within a .chamberrormedpartly atleast, by this bellows.'Two clutch members. onev supported for free... rotation andtheother xedfor rotation A with `thedriving member, arev adapted to be movedrelative to..each other. on expansion or contraction of the bellowsforvarying the drive connection between the. driving member-anda driven"member. The 'clutchwrnernbers may be provided with surfaces engageablewith each other for effecting drive, or the adjacent faces of the clutchmembers may be provided with ns which are variably coupled by a liquid,such as oil.

An object of my invention is to provide an improvedclutch mechanism.Another object is to provide a clutch mechanism which is operative inresponse to changes in a variable condition for controlling the drive ofa driven member from a driving member. Still another object is toprovide a clutch mechanism having a device xed for rotation with adriving member and operating in response to changes in temperatura; for,controllingthe connection of a driven member in driven relation with adriving member. Other objects will appear in the course of the followingdescription- In the accompanying drawing there are shown for. purposesofillustration two forms which my invention may.'k assumein Dlratise.

In this drawing:

Fig. 1 is a sectional View showing one form of my improved clutchmechanism associated with a portion of the, cooling system of a motorfor controlling theoperation of a fan.

Fig. 2 is a 4sectional view of another form of my improved clutchmechanism.

As shown in,L Fig. 1, av pulley I is provided with an axially`projecting portion 2 which is rotatably ysupported by a plate v3attached as by screws 4to acylinder block 5 of a motor. The plate 3coversa portion of the passage means 6 through whichcooling wateris-circulated, and attached tothe inner end of the projecting portion 2isa member 8 which is adapted to pump water through the passage meanswhen rotated. The pulley I is driven continuously from the power shaftof the motor through a belt, not sllnwri, A reces-s l Il)l is formed inthe pulley, and ya bore Il extends through the portion 2 fromV thebottom of the recess to a point adjacenty ,theY pump member` B.Connected in fluid tight relation to the bottom of the recess it issa.bellows I2 having` itsv interior communicating with the bore II. IfAdesired, there may be provided instead a bulb which is sealed to the endofthe `bellows and which rltsloosely withinthe. bore II. Thisarrangement permits an easyvreplacement of parts when necessary. Thespace within thev bellows and the bore Il or the bulb, if the lattery isused, islled with a liquid which expands when its ytemperature isincreased. Arranged within therecess I0 adjacent the bellows is aclutch;element Informed integral with a shaft I5 which is journaled in abearing I6 carried by the hub portions I'I of a clutch plate I8attached, as by screws I9, to the pulley I. The surface of the clutchelement adjacent the plate I8 is recessed so as to provide a projectingannular portion 20 at its outer periphery for engaging the inner surfaceof the plate. If desired, there may be provided on the clutch elementand plate a friction material which provides suitable clutching actionwhen they are moved into engagement with each other. The end of thebellows adjacent the clutch element is rounded, as shown, so as toreduce as much as possible the friction between them when they rotaterelative to each other. Connected to the shaft I5 is a fan 2I fordelivering cooling air over the motor when driven. To prevent the escapeof cooling water from the passage means 6 along the portion 2, there isprovided a packing 23 which is held in fluid tight engagement with theportion 2 by a collar 24 threaded upon a hub portion 25 of the plate 3.

When the temperature of the motor is sufciently low, the bellows I2remains contracted so that the clutch element I4 is free of the plateI8. As the temperature increases, the volume of the liquid increases andexpands the bellows to move the clutch element toward the plate I9. At apredetermined high temperature, the projecting portion on the clutchelement is forced against the plate I8 to eifect a driving of the fan 2lwith the pulley I.

In Fig. 2 there is shown a pulley 30 adapted to be driven continuouslyby a motor and having'a hub portion 3| in which there is journaled ashaft 32 to which a fan must be connected. The pulley is recessed at 33to receive a clutch element 34 fixed to the shaft 32. Attached to thepulley by any suitable means, not shown, is a casing member 35 whichcooperates with the recess 33 to form a closed chamber 36. A clutchelement 38 is arranged within the casing 35 and is keyed to the latterat 39 so that it rotates with the casing but is adapted to move axiallythereof. A projecting portion 40 on the casing may be extended into thewater passage of a motor and be rotatably supported in the same manneras the projection 2 of Fig. l. A bore 4I is provided in the portion 40for receiving a bulb `152 which is sealed to one end of a bellows 44arranged in the housing and acting against the clutch member 38. Anannular plate 45 of spring steel is connected to the housing in anysuitable manner at the end of the bore 4I and is xed to the clutchelement 38 for holding the latter normally in a position away from theclutch element 34. Formed on the adjacent faces of the clutch elementsare fins 4l, and the chamber 36 is partially lled with a liquid, such asoil, to provide a coupling of the clutch elements by the action of theliquid on the ns. The interior of the bellows and the bulb 42 is filledwith a liquid which expands on an increase in temperature.

When the temperature is low, the clutch element 36 is held in a positionnear the left hand end of the housing 35 so that very little coupling ofthe clutch elements is obtained. As the temperature increases, thebellows 44 acts to move the clutch element 36 against the action of thespring member 45 toward the clutch element 34. The level of the liquidbetween the clutch elements rises and gradually increases the couplinguntil,

at a predetermined temperature, the shaft 32 is 6 driven at the samespeed as the pulley 30.

While there have been shown in this application two forms which myinvention may assume in practise, it will be understood that theinvention may be modified and embodied in various other forms withoutdeparting from its spirit or the scope of the appended claim.

What I claim as new and desire to secure by United States Letters Patentis:

A clutch mechanism for controlling the driving of a fan in response tochanges in the temperature of a motor comprising, in combination, adriving pulley having a projecting portion rotatably supported by themotor and subjected to the heat of the latter, an enclosed chamberwithin said pulley, a driven member rotatably supported by said drivingmember and adapted to have a fan connected thereto, a clutch element xedto said driven member and fitting freely within said chamber, a clutchelement xed for rotation with said driving member and movable bodilywithin said chamber relative to said rst mentioned clutch element forvarying the volume of the space within said chamber, means foryieldingly urging said last mentioned clutch element to a positionremote from said rst mentioned clutch element, an expansible chamberdevice in said chamber subjected to the heat of said projecting portiona liquid lling said expansible chamber device and expanding on anincrease in temperature, said expansible chamber device operating onexpansion to move said last mentioned clutch element toward said firstmentioned clutch element a liquid filling said chamlber to `differentlevels depending upon the relative positions of said clutch elements,and ins on the adjacent faces of said clutch elements for effecting avariable coupling of said clutch elements through the liquid in saidchamber.

CLARENCE JOHNSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 818,828 Kasson Apr. 24, 19061,199,359 Fottinger Sept. 26, 1916 1,265,271 Snyder May 7, 19181,701,403 Coykendall Feb. 5, 1929 1,820,035 Stokes Aug. 25, 19311,921,042 Roos Aug. 8, 1933 2,047,028 Metcalf July 7, 1936 2,275,204Smirl Mar. 3, 1942 2,376,939 Ricart May 29, 1945 2,406,486 Bonham Aug.27, 1946 2,512,360 McLean June 20, 1950 FOREIGN PATENTS Number CountryDate 18,344 Great Britain Oct. 15, 1900

